The invention relates generally to methods, systems, and apparatus for identifying and characterizing rotors associated with heart arrhythmias such as atrial fibrillation. Some methods described herein are suitable for classifying rotors as substrate rotors, which may significantly influence arrhythmias, and non-substrate rotors, which may not strongly influence arrhythmias.
In the last few years, scientific understanding of atrial fibrillation has discovered that the electrical activity in the heart during atrial fibrillation is not complete chaos as was once accepted under the Moe model of random wavelets of electrical activity causing atrial fibrillation. Rather, there are local organized electrical drivers of atrial fibrillation. Recent research has revealed that electrical patterns in the heart, commonly referred to as rotors, play an important role in many cases of fibrillation, particularly persistent atrial fibrillation. Currently, surgical systems are available that modify cardiac tissue during treatment using RF energy, cryo, laser, direct current (DC), stem-cells, or drugs. In some situations modifying, ablating, or “burning” a rotor can significantly improve cardiac function by returning the patient to normal sinus heartbeat rhythm.
Known surgical techniques, however, have inconsistent results; ablation of some rotors results in significant changes in heart rhythm, while ablation of other rotors does not have a significant effect. Current medical equipment and techniques cannot identify which rotors will have a significant effect if ablated. A need therefore exists for methods, systems, and apparatus for identifying and characterizing rotors. Furthermore, a targeted approach to treating rotors in atrial fibrillation patients will shorten treatment procedure times, reduce cost of procedures, reduce the need for repeat procedures, preserve heart tissue, and enable patients to live longer and fuller lives.